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To further study the biological function of interferon-gamma (IFN-γ) in the Chinese sturgeon (Acipenser sinensis), we conducted a transcriptome analysis of primary macrophages induced by IFN-γ using Illumina sequencing technology. We obtained 88,879 unigenes, with a total length of 93,919,393 bp, and an average length of 1,057bp. We identified 8,490 differentially expressed genes (DEGs) between the untreated and IFN-γ-treated macrophages, with 4,599 upregulated and 3,891 downregulated. Gene ontology (GO) analysis showed that 4,044 DEGs were enriched in the biological, cellular components, and molecular function categories. Kyoto Encyclopedia of Genes and Genomes (KEGG) identified 278 immunity-related pathways enriched for the DEGs. According to the GO enrichment results, eight key immunity-related genes were screened for verification using qPCR. Results indicate that IFN-γ can activate macrophage Interferon Regulatory Factors (IRFs) and type I interferon (IFN-I), activate RIG-I-like and Toll-like receptor-related pathways, and improve the antiviral ability of macrophages in Chinese sturgeon. [ABSTRACT FROM AUTHOR]

Adenosine deaminases acting on tRNAs (ADATs) are involved in the formation of inosine in tRNAs, and they are members of the adenosine deaminase acting on RNA (ADAR) family of RNA editing enzymes. In this study, we analyzed and characterized two ADAT genes, AdADAT2 and AdADAT3, from Dabry's sturgeon (Acipenser dabryanus). The full‐length cDNAs of AdADAT2 and AdADAT3 were 1704 and 1402 bp, respectively, and they encoded putative proteins of 188 amino acids and 355 amino acids, respectively. AdADAT2 and AdADAT3 genes contain six exons and two exons, respectively. The deduced amino acid sequences exhibit signature features of three residues (generally, one histidine and two cysteines) embedded in three characteristic motifs (motif Ⅰ, Ⅱ, and Ⅲ). AdADAT2 and AdADAT3 mRNAs were expressed ubiquitously in the tissues of healthy A. dabryanus, with elevated levels in the intestine, middle kidney, head kidney, and spleen. In response to polyinosine‐polycytidylic acid (poly I:C), the AdADAT2 mRNA level was significantly upregulated at 6 h post‐stimulation (hps), but the AdADAT3 mRNA level was prominently downregulated at 6 hps. The different responses of the two genes to poly I:C indicate that they have different defense mechanisms against viruses. [ABSTRACT FROM AUTHOR]

Dabry's sturgeon (Acipenser dabryanus) represents an ancient Actinopterygian lineage that are termed "living fossils". Many diseases have been found in Dabry's sturgeon. In the present study, genes encoding interleukin (IL)‐16 and IL‐17D in Dabry's sturgeon were identified by RNA‐sequencing. Phylogenetic tree analysis suggested that they clustered together with the corresponding pro‐IL‐16 proteins and IL‐17D proteins from other fish. Sequence analysis revealed that IL‐17D protein was more conserved than pro‐IL‐16. Dabry's sturgeon pro‐IL‐16 contains four putative PDZ domains and do not include signal peptides, while IL‐17D only possesses signal peptides (1–25 aa). The expression patterns of IL‐16 and IL‐17D genes were investigated in Dabry's sturgeon to reveal their functions in disease. The expression level of IL‐16 showed no significant changes in embryos; however, the high expression level of IL‐17D at 0–14 hpf (hours post fertilization) implied the existence of maternal expression in the oocyte and an association with embryonic development. Tissue distribution analysis revealed that IL‐16 and IL‐17D proteins have potential functions in immune and non‐immune tissue compartments. IL‐16 and IL‐17D had different fold changes in primary spleen leukocytes after polyinosinic:polycytidylic acid (poly I:C) and lipopolysaccharide (LPS) administration, which suggested that IL‐16 has a stronger antiviral capability compared with its antibacterial response, and IL‐17D has a stronger antibacterial capability compared with its antiviral response. IL‐16 showed an earlier response to virus compared with IL‐17D, and IL‐17D showed earlier and shorter response to bacteria compared with IL‐16. Our findings suggested the roles of IL‐16 and IL‐17D in Dabry's sturgeon, and provided the theoretical basis for the prevention and control of diseases of Dabry's sturgeon. [ABSTRACT FROM AUTHOR]

Liver-expressed antimicrobial peptide 2 (leap-2) is an evolutionarily ancient molecule that acts as the key component in vertebrate innate immunity against invading pathogens. Leap-2 has been identified and characterised in several teleosts, but not yet in chondrosteans. Herein, the complete coding sequences of leap-2b and leap-2c were identified from expressed sequence tags (ESTs) isolated from Dabry's sturgeon ( Acipenser dabryanus ) and Chinese sturgeon ( A. sinensis ), designated as adleap-2b, adleap-2c, asleap-2b, and asleap-2c, respectively. Adleap-2b and adleap-2c sequences share 98% and 100% sequence identity with asleap-2b, and asleap-2c, respectively. Sequence alignment revealed that all four genes contain four cysteine residues, conserved in all fish leap-2 homologs, that form two disulfide bonds. Comparative analysis of the exon-intron structure revealed a three exon/two intron structure for that leap-2 genes in animals, but intron 1 is much longer in sturgeons than in other species. The adleap-2c gene was expressed mainly in the liver of Dabry's sturgeon, and transcription of adleap-2c was significantly up-regulated ( p  < 0.05) in the liver and midkidney in response to Aeromonas hydrophila challenge. These results suggest adleap-2c may contribute to the defence against pathogenic bacterial invasion. The findings further our understanding of the function of adleap-2c and the molecular mechanism of innate immunity in chondrosteans. [ABSTRACT FROM AUTHOR]

Dabry's sturgeon ( Acipenser dabryanus ) is mainly distributed in the upper Yangtze River. Although extensively farmed, little information is available on its innate immune system. In this study, we conducted de novo transcriptome assembly of the head kidney to create a comprehensive dataset for A. dabryanus . A total of 51,324,686 high quality reads were obtained from head kidney cDNA library by the Illumina sequencing platform and 131,261 unigenes were determined to contain complete ORFs. The complete coding sequences of g- and c-type lysozymes were identified from unigenes, and designated as ADLysG and ADLysC. Aeromonas hydrophila infection of Dabry's sturgeon caused a significant increase (P < 0.05) in blood for both lysozyme types, confirming their active defensive role against bacterial infections. This research provides the first characterization of these enzymes in an ancestral chondrostean. These data suggest that ADLysG and ADLysC have the potential for immune defense system against bacterial infection. [ABSTRACT FROM AUTHOR]

Mycobacterium ulcerans ecovar Liflandii ( Mu Liflandii) is emerging as a non-mycobacterial pathogen in amphibians. Here, we make the first report on the prevalence of a new strain of Mu Liflandii infection in Chinese sturgeon. All the diseased fish showed the classic clinical symptoms of ascites and/or muscle ulceration. A new slow-growing and acid-fast bacillus ASM001 strain was obtained from the ascites of infected fish; this strain demonstrated pathogenicity when tested in hybrid sturgeon. The complete genome sequence of Mu Liflandii ASM001 is a circular chromosome of 6,167,296 bp, with a G + C content of 65.57%, containing 4518 predicted coding DNA sequences and 999 pseudo-genes, 3 rRNA operons, and 47 transfer RNA sequences. In addition, we found 245 copies of IS2404, 34 microsatellites, and 36 CRISPR sequences in the whole Mu Liflandii ASM001 genome. Among the predicted genes of Mu Liflandii ASM001, we found orthologs of 203 virulence factors of clinical Mu Liflandii 128FXT operating in host cell invasion, modulation of phagocyte function, and survival inside the macrophages. These virulence factor candidates provide a key basis for understanding their pathogenic mechanisms at the molecular level. A comparative analysis that used complete, existing genomes showed that Mu Liflandii ASM001 has high synteny with Mu Liflandii 128FXT. We anticipate the availability of the complete Mu Liflandii ASM001 genome sequence will provide a valuable resource for comparative genomic studies of Mu Liflandii isolates, as well as provide new insights into the host, ecological, and functional diversity of the genus Mycobacterium . [ABSTRACT FROM AUTHOR]

In the present study, we aimed to screen the potential probiotic Bacillus subtilis isolated from the gut of healthy fish using in vitro assays and to evaluate its effect on Dabry's sturgeon (Acipenser dabryanus) using in vivo feeding experiments. Among the isolates, B. subtilis BSth-5 and BSth-19 exhibited antimicrobial effect against four sturgeon-pathogenic bacteria, including Aeromonas hydrophila , A. veronii , A. media , and Streptococcus iniae. The cell number of B. subtilis BSth-5 and BSth-19 changed little after 2 h of exposure to pH 3.0 or fresh Dabry's sturgeon bile at 2.5% and 5.0%. Meanwhile, B. subtilis BSth-5 and BSth-19 produced extracellular protease, cellulose, and lipase. And it was proved that B. subtilis BSth-5 and BSth-19 were harmless after injection of Dabry's sturgeon. One group of Dabry's sturgeon was fed a control diet and two groups were fed experimental diets containing 2.0 × 108 CFU/g BSth-5 (T1 group) or BSth-19 (T2 group) for 8 weeks. No significant differences in final weight, weight gain rate, and special growth rate were observed in the T1 and T2 groups compared to the control group (P > 0.05), but a significant improvement in survival rate was detected after 4 and 8 weeks of feeding (P < 0.05). After 8 weeks, serum total antioxidant capacity, total superoxide dismutase activity, and IgM levels were significantly higher in the T1 and T2 groups compared to the control group (P < 0.05). Moreover, serum lysozyme activity was significantly higher in the T1 group relative to the control group during the whole experiment period (P < 0.05); however, the differences were not significant between the T2 and control groups (P > 0.05). Serum malondialdehyde levels in the T1 and T2 groups were significantly lower than those in the control group after 4 weeks (P < 0.05). Sturgeons in the T1 and T2 groups showed a higher survival rate after Aeromonas hydrophila infection. To summarize, dietary supplementation with BSth-5 and BSth-19 could enhance the survival rate, antioxidant activity, serum immunity, and disease resistance in A. dabryanus. Image 1 [ABSTRACT FROM AUTHOR]

Abstract In the present study, we identify three type I interferon (IFN) genes (Ad/As IFNe1-3) and a type II IFN gene (Ad/As IFNγ) from the Dabry's sturgeon (Acipenser dabryanus) and the Chinese sturgeon (Acipenser sinensis). Sequence analysis revealed that Ad/As IFNe1–3 and Ad/As IFNγ contain several conserved characteristics, including signal peptides, interferon alpha, beta, and delta (IFabd) domains, and N-glycosylation sites. Ad/As IFNe1-3 belongs to the type I IFN group I subgroup, possessing two conserved cysteines residues (C1 and C3), and Ad/As IFNγ contained a conserved nuclear localization sequence (NLS) motif. Ad/As IFNe1-3 and Ad/As IFNγ contain signature motifs indicative of their corresponding IFN group. The Ad/As IFNe1-3 and Ad/As IFNγ genes were found to consist of 5 exons/4 introns and 4 exons/3 introns, respectively. These IFNs were separated by four phase 0 introns (type I IFN) and three phase 0 introns (type II IFN). The sequences of IFNe1-3 and IFNγ from the Dabry's sturgeon and the Chinese sturgeon were closely aligned, suggested that these two species are closely related. Phylogenetic analysis revealed that Ad/As IFNe1-3 and Ad/As IFNγ clustered together with the corresponding homologous proteins from other fish species. Ad IFNe1-3 were found to be high expressed in early embryonic development, suggesting that Ad IFNe1-3 might indicate maternal transmission, while Ad IFNγ may not mediate embryonic development. Tissue distribution analysis revealed that Ad IFNe1-3 and Ad IFNγ carry out biological functions in immune and non-immune tissues compartments. Ad IFNe1-3 and Ad IFNγ can be stimulated by polyinosinic-polycytidylic acid (poly I:C) and lipopolysaccharides (LPS). Ad IFNe1-3 have stronger antiviral activity than Ad IFNγ, and Ad IFNγ has a stronger antibacterial activity than Ad IFNe1-3. The differential responses of these genes to poly I:C and LPS suggest differences in the mechanisms of defense against viruses and bacteria. Highlights • In this study, type I and type II IFNs from Dabry's sturgeon and Chinese sturgeon were identified and their molecular characterizations were analyzed. • Ad / As IFNe1-3 and Ad / As IFNγ possess prototypical type I and II IFN sequence characteristics, such as signal peptide, IFabd domains, and conserved cysteine. • Ad IFNe1-3 have stronger antiviral capability than Ad IFNγ, and Ad IFNγ has stronger antibacterial activity than Ad IFNe1-3. [ABSTRACT FROM AUTHOR]

Teleost fish possess a diversity of type Ⅰ interferons (IFNs) repertoire, which play a crucial role in antiviral and antimicrobial immune responses. In our previous study, IFNe1-3 and IFNb were identified and cloned from Chinese sturgeon (Acipenser sinensis), an acipenseriform fish. However, the absence of Chinese sturgeon genome data has left the question of whether there are other type Ⅰ IFN members in this species unresolved. In this study, we have identified and characterized a novel IFN, IFNf in Chinese sturgeon (As IFNf). Bioinformatics analysis revealed that the As IFNf contains a unique disulfide bond (2 cysteines) located in the second exon and fifth exon region, distinguishing it from other reported teleost type I IFNs. Meanwhile, qPCR results showed that As IFNf mRNA was detectable in all examined tissues and up-regulated in the spleen or kidney in response to poly I: C, Citrobacter freundii , and Spring Viremia of Carp Virus (SVCV), but not by LPS. Furthermore, compared to recombinant As IFNe2 protein (r As IFNe2), r As IFNf exhibited a stronger protective effect on Chinese sturgeon fin cells against SVCV and also induced higher expression of antiviral genes Mx and viperin. Importantly, As IFNf displayed characteristics similar to antimicrobial peptides (AMPs) with a positive charge and demonstrated a broad spectrum of antimicrobial activity in vitro. These findings provide a theoretical foundation for understanding the primitive structure and function of interferon, as well as deepening our comprehension of the innate immune system and disease defense in the endangered Chinese sturgeon. • A new type I interferon, IFNf was identified in the Chinese sturgeon. • As IFNf, Group Ⅱ interferon, has only one disulfide bond. • As IFNf had AMPs-like features and showed an antimicrobial activity in vitro. [ABSTRACT FROM AUTHOR]

Mycobacterium marinum is an opportunistic pathogen and can infect marine and freshwater fish. In this study, an acid-fast bacillus strain was isolated from the moribund Acipenser sinensis and identified as M. marinum via specific plate culture and phylogenetic analysis of 16S rRNA. M. marinum exhibited pathogenicity in Chinese sturgeon and hybrid sturgeon (A. schrenckii ♀ × A. baerii ♂). The histopathology results showed that granulomatous nodules were observed in the liver, spleen and kidney of the Chinese sturgeon after M. marinum infection. Nuclear necrosis and large production of hemosiderin appeared in the liver. The medullary structure of the spleen was disordered. The glomerulus was deformed and disintegrated, and the glomerular lumen was dilated in the kidney. The expressions of IFN-e1, IFN-γ, TNFα1, TNFα2, IL-1β, and IL-6 of Chinese sturgeon were significantly upregulated by M. marinum in vivo and in vitro. The whole blood ELISA detection method was constructed by IFN-γ polyclonal antibody. The infection of M. marinum in hybrid sturgeon could be judged by detecting the concentration of IFN-γ in plasma. In summary, M. marinum has a strong pathogenicity to sturgeon and could induce the immune response of the host. The sturgeon IFN-γ-ELISA detection method was expected to become a tool for diagnosing M. marinum infection in sturgeon. This study could provide the scientific basis for effectively controlling and reducing the pathogenic M. marinum disease of sturgeon in aquaculture. • Mycobacterium marinum is an infectious agent for Acipenser sinensis that could cause tissue lesions and form granuloma. • M. marinum induced several key pro-inflammatory cytokines, suggesting that M. marinum induced complex inflammatory response. • IFN-γ-ELISA detection method was conducted and could correctly judge whether the sturgeon was infected with M. marinum. [ABSTRACT FROM AUTHOR]

Abstract Dabry's sturgeon (Acipenser dabryanus), as a living fossil, is considered a critically endangered aquatic animal in China. To date, the immune system of this species remains largely unknown, with limited available sequence information. In addition, increasing incidence of bacterial pathogenic diseases has been reported. Hence, the present study aimed to characterize comprehensively transcriptome profile of the head kidney from Dabry's sturgeon infected with Aeromonas hydrophila using Illumina platform. Over 42 million high-quality reads were obtained and de novo assembled into a final set of 195240 unique transcript fragments (unigenes), with an average length of 564 bp. Approximately 41702 unigenes were annotated in the NR NCBI database. Dabry's sturgeon unigenes had the highest number of hits with 14365 (34.45%) to Lepisosteus oculatus. The 195240 unigenes were assigned to three Gene Ontology (GO) categories: biological process, cellular component, and molecular function. Among them, 27770 unigenes were clustered into 26 Eukaryotic Orthologous Group (KOG) functional categories, and 36031 unigenes were mapped to 335 known Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. After A. hydrophila administration, 1728 differentially expressed unigenes were identified, including 980 upregulated and 748 downregulated unigenes. Further KEGG enrichment analysis of these unigenes identified 16 immune-related pathways, including the Toll-like receptor signaling pathway, chemokine signaling pathway, complement and coagulation pathway, RIG-I-like receptor signaling pathway, and NOD-like receptor signaling pathway. 20 DEGs were selected and their expression patterns are largely consistent with the transcriptome profile analysis, which clearly validated the reliability of the DEGs in transcriptome analysis. This work revealed novel gene expression patterns of Dabry's sturgeon host defense and contributes to a better understanding of the immune system and defense mechanisms of Dabry's sturgeon in response to bacterial infection. The results provide valuable references for studies in sturgeons that lack complete genomic sequences, and could also be helpful for the analyzing evolution among cartilaginous and teleost fish. Highlights • The head kidneys transcriptome of Dabry's sturgeon were constructed using Illumina XTen platform. • Totally, 195240 unigenes were obtained from the transcriptome. • Toll-like signaling pathway, Chemokine signaling pathway, RIG-I-like and NOD-like receptor signaling pathways were analyzed. • A total of 1728 differentially expressed unigenes were identified, including 980 upregulated and 748 downregulated unigenes. [ABSTRACT FROM AUTHOR]

Abstract Dabry's sturgeon (Acipenser dabryanus) is a useful model for the study of fish evolution, as it is one of the most primitive actinopterygian species. However, studies of the immune system of this fish are limited. Here, we identified three toll-like receptors (adaTLR21, adaTLR22, and adaTLR25) from Dabry's sturgeon. The three sturgeon TLRs had characteristic TLR features, including a signal peptide, several leucine rich repeat (LRR) domains, a transmembrane domain, and a Toll/interleukin-1 receptor (TIR) domain. Although the predicted amino acid sequences encoded by the sturgeon adaTLR21, adaTLR22, and adaTLR25 had somewhat low levels of sequence identity and similarity with TLRs from other fish species, the three sturgeon TLRs fell in well-supported clades with other teleost TLRs in our neighbor-joining phylogenetic tree. Real-time quantitative PCR showed that the three sturgeon TLRs were ubiquitously expressed in all examined tissues from healthy adult sturgeon, but that their expression patterns varied greatly among the different tissues. The three sturgeon TLRs were also expressed across all embryonic developmental stages that were examined, but their expression levels differed between developmental stages. All three TLRs were upregulated in head–kidney primary leucocytes following lipopolysaccharide (LPS) and polyinosinic: polycytidylic acid (polyI:C) stimulation. To the best of our knowledge, this is the first characterization of these three TLRs in Darby's sturgeon. Our results provide a framework for further studies of TLR ligand specificity and signaling pathways in sturgeon, and increase our understanding of the functional evolution of TLRs in vertebrates. Highlights • TLR21, TLR22 and TLR25 were identified from the endangered fish cipenser dabryanus. • Sequence features of TLR21, TLR22 and TLR25 were analyzed. • Expression patterns of TLR21, TLR22 and TLR25 in normal tissues were analyzed. • Expression patterns of TLR21, TLR22 and TLR25 in embryonic stages were analyzed. • Expression patterns of TLR21, TLR22 and TLR25 in the HK leucocytes were analyzed. [ABSTRACT FROM AUTHOR]

Teleost fish have more complex interferon receptor systems than mammals. In the present study, genes encoding four cytokine receptor family B (CRFBs) and two interferon gamma receptors (IFNGRs) in Dabry's sturgeon ( Acipenser dabryanus ) were identified by RNA-sequencing. Sequence analysis revealed that the Dabry's sturgeon CRFBs and IFNGRs contained several conserved characteristics features, including signal peptides and a transmembrane domain. Phylogenetic analysis suggested that they belong to the CRFB3, CRFB5, and IFNGR protein families, and were named CRFB3a, CRFB3b, CRFB5a, CRFB5b, IFNGR1, and IFNGR2. The expression patterns of the CRFB and IFNGR genes were investigated in Dabry's sturgeon. The expression levels of CRFB5a, CRFB5b, and IFNGR1 showed no significant changes, suggesting that those genes do not mediate embryonic development. By contrast, the high expression levels of CRFB3a, CRFB3b, and IFNGR2 in the fertilized egg, 16-cell phase, and initial blastula stage implied the existence of maternally expression in the oocyte and association with embryonic development. Tissue distribution analysis revealed that the CRFB and IFNGR proteins have potential functions in immune and non-immune tissue compartments. Comprehensive analysis in Dabry's sturgeon revealed that the expression fold changes of CRFB3a, CRFB3b, CRFB5a, and CRFB5b in Dabry's sturgeon stimulated with poly I:C were higher than those in fish administrated with lipopolysaccharide (LPS). Conversely, the fold changes IFNGRs mRNA levels stimulated with LPS were higher than those in fish administrated with poly I: C. CRFB5a and IFNGR2 genes showed the earliest responses to the poly I: C, and the CRFB5a and IFNGR1 genes showed the earliest responses to LPS. These results implied that CRFB5a has important role in the IFN immune response. Our findings indicated that the Dabry's sturgeon CRFB and IFNGR genes have important functions in antiviral and antibacterial immune responses. The differential responses of these genes to poly I: C and LPS implied differences in the defense mechanisms against viruses and bacteria. [ABSTRACT FROM AUTHOR]

Chinese sturgeon (Acipenser sinensis) is an indigenous species of China and is listed as a critically endangered species. Recently, second filial generations of Chinese sturgeon in the Yangtze River Fisheries Research Institute suffered from a severe disease. In this study, two kinds of pathogenic bacteria were isolated from diseased sturgeon and identified as Plesiomonas shigelloides and Citrobacter freundii , based on 16S rDNA gene sequence alignment analysis. Antimicrobial susceptibility testing showed that P. shigelloides was resistant to ampicillin, penicillin, midecamycin, oxacillin, and clindamycin; and sensitive to tocefatriaxone, piperacillin, cefoperazone, cefazolin, and ciprofloxacin. C. freundii was resistant to ampicillin, penicillin, midecamycin, oxacillin, and clindamycin; and sensitive to chloramphenicol, cefuroxime, norfloxacin, ciprofloxacin, and ceftazidime. The median lethal dose (LD 50) values of P. shigelloides and C. freundii were 4.50 × 103 colony forming units (CFU)/g and 3.20 × 103 CFU/g, respectively. Clinical symptoms of challenged sturgeons were the same as those of naturally infected sturgeons. Histopathological examination disclosed severe damage in the viscera of P. shigelloides and C. freundii- infected sturgeons. This is the first report suggesting that P. shigelloides infection is associated with mortality of Chinese sturgeon. The results of this study revealed the pathogenesis and severe pathogenicity of P. shigelloides and C. freundii in cultured Chinese sturgeon, and offer insights into the prevention and treatment of bacterial infection caused by P. shigelloides and C. freundii in cultured sturgeons. • P. shigelloides and C. freundii are infectious agents of Chinese sturgeon. • P. shigelloides and C. freundii cause damage to the viscera of Chinese sturgeon. • The median lethal dose (LD 50) of P. shigelloides was 4.50 × 103 CFU/g. • The median lethal dose (LD 50) of C. freundii was 3.20 × 103 CFU/g. [ABSTRACT FROM AUTHOR]

The interferon receptor system in teleost fish is more complex than that in mammals. In the present study, we identified 13 cytokine receptor genes (10 interferon receptor genes and 3 IL10R2-like genes) from Chinese sturgeon (Acipenser sinensis) using RNA-sequencing. Sequence analysis indicated that these receptors had conserved domains, including signal peptides, FNⅢ, and transmembrane domains. Phylogenetic analysis suggested that they belonged to the cytokine receptor family. In the present study, we named them IFNAR1-like (CRFB5a, CRFB5b), IFNAR2-like (CRFB3a, CRFB3b), IFNGR1-like (IFNGR1), IFNGR2-like (CRFB6a, CRFB6b/IFNGR2-1, CRFB6c/IFNGR2-2, CRFB6d/IFNGR2-3, CRFB6e/IFNGR2-4) and IL10R2-like (CRFB4a, CRFB4b, CRFB4c), respectively. Constitutive expression analysis revealed that these receptor genes had potential functions in immune and non-immune tissue compartments. After stimulating with Poly (I:C), the expression fold changes of CRFB3a , CRFB4a , CRFB4b , CRFB5b , and CRFB6e / IFNGR2-4 in Chinese sturgeon were higher than those of other receptor genes, which revealed that these five genes had important functions in the immune process to resist virus invasion in the host. After stimulating with IFN gamma, the expression fold changes of CRFB3a , CRFB4a , and CRFB6b / IFNGR2-1 were higher than those other receptor genes. Based on other teleost fish interferon receptor models, we speculated that IFNAR1-like (CRFB5a, CRFB5b) and IFNAR2-like (CRFB3a, CRFB3b), comprised Chinese sturgeon type Ⅰ IFN receptors; and IFNGR1-like (IFNGR1) and IFNGR2-like (CRFB6/IFNGR2) comprised Chinese sturgeon type Ⅱ IFN receptors. • This report first described thirteen interferon receptors expression pattern from the endangered fish Chinese sturgeon. • CRFB3a and CRFB3b in ancient fish have the similar function as CRFB1 and CRFB2 in other teleosts. [ABSTRACT FROM AUTHOR]